HOW WE HEAR
The ear is divided into three parts:the outer, middle and inner ear.
THE OUTER EAR
It consists of the visible parts called the pinna .The pinna collects sounds and directs it into the external ear canal. The ear canal makes the sound louder and further directs sound towards the eardrum (tympanic membrane). The ear drum acts as a music drum.
The ear drum vibrates in response to the movements of sound waves entering the ear canal. There are also three bones in the middle ear. They include, the malleus (hammer), the incus (anvil) and the stapes(stirrup),magnifying the movements of the eardrum and transmitting the motion to the inner ear.
THE INNER EAR
The cochlea is the actual sensory organ of the hearing and also located in the inner ear. Te members of the cochlea are filled with fluid. As the bones in the middle ear moves in response to sound waves, they cause the fluid in the cochlea to also move.This stimulates thousands of sensory hair cells which produce small electrical charges. This electrical charges travel along the auditory nerve to the brain where they are processed as the"sound" we hear.
DISEASES OF THE EAR AND HEARING LOSS
Foreign objects e.g. beads, seeds
Pain and or pas in the ear coming out
Itching in the ear.
- Affecting outer and middle ear.
- Sounds are not conducted well into the inner ear
- Can be treated and cured.
2. SENSOR NEURAL HEARING LOSS.
- Can not be medically treated.
- Require hearing aids in order to hear well
- Child may not develop speech and language if not attended early in life
- Adult get great problems in communication.
- Children perform poorly in class.